WASHINGTON -- There was a common theme in the dressing rooms after the game Thursday night at Verizon Center, but it wasn't just celebration -- it was also a sense of relief.

The Washington Capitals defeated the Florida Panthers, 4-2, but both clubs were victorious on this night. Thanks to a win by the Philadelphia Flyers against the Buffalo Sabres, both Washington and Florida locked up the final two spots in the Eastern Conference for the 2012 Stanley Cup Playoffs.

"It really has weighed heavily on our minds," Washington forward Jason Chimera said. "We're watching the scoreboard when we're up 3-0 and (Buffalo) is up 1-0 and you're like, 'C'mon.' Then all of a sudden, (Philadelphia) was up 2-1 and it was like, 'Geez, we've got to get this done.' The intensity picked up a little from there."

Added Florida forward Stephen Weiss: "I don't care (about the loss). I couldn't care how it happened. All you got to do is get in, and anything can happen."

The Panthers will clinch the Southeast Division title for the first time in franchise history with at least a point Saturday against the Carolina Hurricanes. Washington can win the Southeast for a fifth consecutive time if the Capitals defeat the New York Rangers and the Panthers lose in regulation.

This is the first trip to the postseason for Florida since the 1999-00 season, and only the fourth time in franchise history. General manager Dale Tallon was hired in May 2010, and began a wholesale renovation of the roster at the trade deadline last season that culminated with a flurry of signings and trades this past summer.

New coach Kevin Dineen was tasked with molding a cohesive team out of all the newcomers, and the Panthers came together much quicker than many pundits expected.

"I'm just especially proud of our players and our staff for working so hard to put this together in such a short time," Tallon said. "We've got all these new players and we had all these injuries, but they kept true to themselves and have been incredible. I'm just real proud.

"We brought them all in here in July for this reason. We didn't know when it was going to happen, but these guys have really done an extraordinary job. I'm especially proud of Stephen Weiss for him. He's deserved this more than anybody."

So many long-tenured Panthers have left in recent seasons, but Weiss was the one who stayed. This was Weiss' 636th career game in the NHL -- all with the organization that selected him fourth in the 2001 NHL Draft -- and it will be his first time in the playoffs.

Weiss has centered Florida's top line this season, along with ex-Capitals wing Tomas Flesichmann and one of Tallon's ex-Chicago imports, Kris Versteeg, and it has been one of the most productive trios in the League.

The Panthers have now lost five in a row and eight of nine games, but are 1-3-5 during that stretch. Fans in Buffalo might not like seeing the 18 overtime/shootout losses at the end of Florida's record, but the Panthers will be playing in mid-April for the first time in more than a decade.

"We've been getting the points and obviously we go to overtime almost every game. It doesn't matter how you get in as long as you get in," Florida defenseman Brian Campbell said. "I got in the back door last year and we almost got that first-round series against the No. 1 seed."

The Capitals were expected to be among the League's elite in 2011-12 -- just as they were for the previous three seasons. It has been a campaign fraught with inconsistent play, coaching changes and injuries.

Still, the Capitals are back in the postseason for the fifth consecutive year. They might not be considered one of the favorites to play for the Stanley Cup, but that expectation hasn't suited them very well in previous playoffs.

Alex Ovechkin scored for the 10th time in the past 15 games, and Alex Semin, who also scored, has nine points in his past seven games. Nicklas Backstrom is also healthy, which could make the Capitals a dangerous team in the coming weeks.

"It has been an up and down season, but now we can start fresh," Chimera said. "We've got all our guys back healthy, and some goalies to heal up, but (Braden Holtby) stood up and did a great job. This is just a great feeling."

While the Capitals's stars are finally healthy, they have new concerns on that front. Tomas Vokoun is already out with a groin injury, and Michal Neuvirth left this contest with a lower-body ailment. Ex-Capitals forward Marco Sturm fell on Neuvirth early in the second period, and he was replaced by Holtby.

Holtby made 14 saves and helped the Capitals hold off a Florida comeback, but he has spent the majority of this season in the American Hockey League and, depending on the status of the other two goalies, could be in net for Game 1. Capitals coach Dale Hunter did not have an update on Neuvirth after the game.

Jay Beagle had the lone goal of the opening period. Troy Brouwer's shot hit Beagle in the slot, and he was able to snap the rebound off the crossbar and into the net before goaltender Jose Theodore could react. It was Beagle's fourth goal of the season, and the signature moment in a period where Washington's fourth line was the best for either side.

Ovechkin made it a 2-0 lead with his 37th goal of the season at 7:49 of the second period. He collected a wayward D-to-D pass by Florida's Dmitry Kulikov and rushed up the left side. He left the puck for Marcus Johansson, went to the net, collected the rebound and flicked it under the crossbar from a tight angle.

Florida had clearly dominated the opening minutes of the period. Neuvirth left the game 5:39 into the period when Sturm fell on his left leg at the top of the crease.

The Panthers continued to control the contest after Holtby replaced Neuvirth, but Kulikov's errant pass to Mike Weaver, who had left the offensive zone, was a turning point.

Washington went on the attack after Ovechkin's goal, and Brooks Laich made it 3-0 exactly two minutes later. Laich, who gained plenty of attention Thursday by stating on a local radio station that Capitals would make the playoffs, ripped a shot from the left circle past Theodore.

Panthers coach Kevin Dineen replaced Theodore with backup Scott Clemmensen, but put his starter back in 91 seconds later during a media timeout.

Florida cut the lead to 3-1 at 15:41 of the second period. Mikael Samuelsson snapped a shot from the left circle past Holtby for his 13th of the season. Ed Jovanovski's knuckling, deflected shot evaded Holtby 42 seconds into the third period to get the Panthers back within a goal.

Semin ended any doubt with 62 seconds left in regulation to make it 4-2. The Panthers already knew they were in the playoffs at that point, because the score from the Flyers-Sabres game was posted on the scoreboard during a stoppage in play.

"We got a taste tonight of what playoff hockey is going to be like," Campbell said. "We got to bring that Saturday to the game and take care of business now and get home-ice advantage here."